body{
  width:400px;
  margin:50px auto;
  font-size:1.1em;
}
input,label,span{
  margin:5px 0;
  padding-left:5px;
  height:30px;
  width:250px
}
span{
  color:red;
}
#perimeter{
  margin-left:-4px
}
#calc{
  margin-left:50px;
  width:60px;
}
#addWidth,#addHeight{
  margin-left:50px;
  color:red;
}
